AB1570 MODERN TREATMENT OF ENTRAPMENT NEUROPATHIES, THE HYDROCHEMICAL NEUROLYSIS
Authors: A. Ould Hennia
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Entrapment neuropathies (E.N) are frequent and often underdiagnosed leading to significant chronic pain and functional impairment impede the quality of life. Commonly occur at the fibro-osseous tunnels through which the nerves course with various static and dynamic factors. Imaging particularly ultrasound can identify an anatomical cause, detect signs of nerve injury, assess its severity and also aid in the percutaneous treatment like our technique: "The hydrochemical neurolysis" (HCN). <h3>Objectives</h3> We present the US-guided hydrochemical neurolysis of E.N to relieve, in most cases, the pain caused by peripheral nerve compression and its consequences by the mechanical release and decompression of the entrapped nerves. This technique involves using US (fast, accessible, reliable, cheap and radiation-free) to find the nerve and guide a needle around the nerve to cut scat tissue and introduce fluid to mechanically push scar tissue ways from the nerve and create separation between the nerve and tissues. With <b>18 G needle</b>, a real mechanical dissection is performed and with the liquid (normal saline) we complete with a hydrodissection. <h3>Methods</h3> Before performing a US-guided HCN, survey imaging should be performed with low or high resolution probes, depending on the depth of the intervention. patient informed and clearly consents. <b>Technique:</b> what I do. <b>Patient positioning:</b> patient positioned in a supine, sitting, or prone posture according to the location of the nerve to be treated. Different positions, pillows and/or pads can be used to restrict movement during the procedure and provide comfort for patient and physician. Identification, marking the skin, disinfection and local anesthesia. The needle entry point is calculated based on the distance and inclination angle of the needle from the skin surface to the target for better and optimal visibility of the needle tip. These settings are variable depending on the superficial or deep situation of the nerve to be treated. The entry site is then marked (with skin marker) as well as the projection of the target at the level of the skin, then the skin area is cleaned and prepared for the using standard sterile technique. The US-probe is covered with a sterile semi-transparent bag and a sterile gel is used for further analysis and intervention. A 25 G needle is used to anesthetize the skin with 1% lidocaine, and is then advanced under US-guidance with an intermittent local injection for anesthesia (and hydrolocation) until the needle comes into contact with the epineurium. The in-plan approach is my favorite. Perineural Hydrolocalization, Adhesiolysis, Hydrodissection and injections. With <b>18 G</b> needle (variable length according to the site to be treated) we inject under low pressure 5-10 ml of liquid (mix of normal saline and 1% lidocaine) between the compressed nerve and the connective-fatty tissue to make the end of my needle clearly seen (<b>hydrolocation</b>), can be repeated for the duration of the procedure. Then with the same needle, we inject 20-60 ml of normal saline all around the nerve and over the entire area where it is compressed to release it completely from all surrounding structures (<b>hydrodissection</b>). <b>Adhesiolysis</b>is carried out when there is scar tissue around the nerve and the hydro-dissection was not effective, in this case a real mechanical needle dissection is carried out or the needle is used like a scalpel to make needling in varying directions all the scar tissue surrounding the nerve. After hydrodissection, we <b>inject</b> corticosteroid (5-10 ml of prednisolone acetate 125 mg) for his anti-inflammatory and anti-fibrotic effect. <h3>Results</h3> In my practice, we have at least 70% good results at 12 months, 20 to 25% require a 2nd session of hydrochemical neurolysis and maybe 10% will resort to surgery. The results of neurolysis seem very interesting, much better than a simple US-guided infiltration and avoids surgery in many cases. <h3>Conclusion</h3> Success with this hydrochemical neurolysis procedure requires knowledge of anatomy, US-imaging. The HCN is a simple, safe, precise, rapid, and effective percutaneous treatment of E.N, a great alternative to surgery. <h3>Acknowledgements</h3> To anesthesiologist who trained me in musculoskeletal ultrasound more than 20 years ago and to all the patients who trusted me to offer them the best care. <h3>Disclosure of Interests</h3> None Declared.